Oblique flow fan

ABSTRACT

The invention belongs to the technical field of fans, in particular to a high-efficiency oblique flow fan. The oblique flow fan comprises fan blades, an air guide cover, directional air guide blades and a housing, wherein the fan blades and the directional air guide blades are connected through a central bearing, the bearing fixed at the center of the conical fan blades passes through a reserved hole in the center of the directional air guide blades and is fixed, the air guide cover is directly stuck at the corresponding position on the housing through the action of a clamping point, and the directional air guide blades and the housing are fixed through screws. The oblique flow fan of the invention reduces sudden change and turbulence of air flow to the greatest extent, doubles the air pressure and energy efficiency of the fan, and effectively reduces noise.

BACKGROUND OF THE INVENTION Field of the Invention

The invention belongs to the technical field of fans, in particular to a high-efficiency oblique flow fan, which is applied to various ventilation devices, equipment and systems.

Background

According to the inclination angle between fan blades and axial direction, fans can be divided into axial flow, oblique flow (also known as mixed flow) and turbine fans. Oblique flow fans are widely used in ventilation devices, equipment and systems with certain wind resistance load due to their large air volume and pressure, good linearity and wide speed regulation range. The general oblique flow fan simply distributes the fan blades in the cylindrical motor housing/cover. The housing is also typically cylindrical. The air inlet and the air outlet have the same diameter, without front and rear wind guide structures. The velocity of the air flow from the forward air to the rear air outlet end of the fan blade changes greatly or even abruptly. The two sides of the fan blade have a large pressure difference, which causes turbulence and noise, and the air outlet flow is spiral, which increases the friction resistance between the air flow and the rear air outlet components, reduces the energy efficiency, and the air pressure is usually below 200 pa, thus limiting its application to a certain extent.

SUMMARY OF THE INVENTION

The technical issues to be solved by the invention are: solve the issues of large pressure difference between the front and rear ends of the fan blades of the existing fan due to large difference in airflow speed, forming turbulence and noise, reducing energy efficiency and the like, and aims to provide a fan with improved structure.

The present invention provides an oblique flow fan, comprising fan blades, an air guide cover, directional air guide blades and a housing, wherein the fan blades and the directional air guide blades are connected through a central bearing, the bearing fixed at the center of the conical fan blades passes through a reserved hole in the center of the directional air guide blades and is fixed, the air guide cover is directly stuck at the corresponding position on the housing through the action of a clamping point, and the directional air guide blades and the housing are fixed through screws.

The technical scheme adopted by the embodiment of the invention further comprises: The fan blades is conical.

The technical scheme adopted by the embodiment of the invention further comprises: The conical fan blades has a taper A of 50°-60°.

The technical scheme adopted by the embodiment of the invention further comprises:

The inclination angle range between the conical fan blade and the axial direction is greater than B1 and less than B2, wherein the inclination angle B1 is 45° and the Inclination angle B2 is 65°.

The technical scheme adopted by the embodiment of the invention further comprises: The number of conical fan blades is odd.

The technical scheme adopted by the embodiment of the invention further comprises: The air guide cover is a bell mouth cone, the air guide cover is close to the fan blades, and the taper D of the air guide cover is 6 to 8° smaller than the taper of the fan blades.

The technical scheme adopted by the embodiment of the invention further comprises: The inclination angle E between the tangent line of the initial arc section of the air guide blade and the axial direction is about 45°.

The technical scheme adopted by the embodiment of the invention further comprises: The number of directional air guide blades is even, which is one more than the number of fan blades.

The technical scheme adopted by the embodiment of the invention further comprises: The housing is cylindrical.

Compared with the prior art, the embodiment of the invention has the following beneficial effects: For the oblique flow fan, the taper of the conical fan blades and motor housing/cover is between 50°-60°; a conical cover is used for air guide in the whole air supply part including the front end of the air blades; the taper is 6°-8° smaller than that of the fan blades; the air supply section between two fan blades is reduced appropriately and gradually in the whole process (the air volume is reduced after compression); the flow rate is kept as consistent as possible when the flow direction is changed; a “siphon effect” is generated at the front and rear ends of the fan blades; the pressure difference between the two sides of the fan blades is minimized; the drive resistance is minimized; at the same time, further, directional air guide blades are adopted at the air outlet end of the fan blades to guide the spiral air flow to axial direct flow, so as to reduce the friction resistance between the air flow and the components with no air, multiply the air pressure and energy efficiency of the fan, and effectively reduce noise.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an assembly schematic view of the oblique flow fan accord to an embodiment of the present invention;

FIG. 2 is a schematic cross-sectional view of the oblique flow fan according to an embodiment of the present invention;

FIG. 3 is a front view of the oblique flow fan according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Referring to FIG. 1 to FIG. 3, the oblique flow fan according to an embodiment of the present invention includes fan blades 1, an air guide 2, directional air guide blades 3 and a housing 4. The oblique flow fan according to another embodiment of the present invention includes fan body 1, an air guide 2, directional air guide blades 3 and a housing 4. The fan blades 1 is conical and may have other shapes. The fan blades 1 and the directional air guide blades 3 are connected by a central bearing (not shown). Bearings fixed in the center of the conical fan blades 1 pass through the reserved hole in the center of the directional air guide blade 3 and are fixed. The air guide cover 2 is directly stuck to the corresponding position on the housing 4 by the action of the blocking point. The connection mode between the directional air guide blade 3 and the housing 4 is fixed by screws or by other means.

The conical blades 1 has a taper A of 50°-60°. The inclination angle range between the conical fan blade and the axial direction is greater than B1 and less than B2, wherein the inclination angle B1 is 45° and the Inclination angle B2 is 65°; namely, the air cutting angle range of the conical blade is greater than C2 and less than C1, wherein the air cutting angle C2 is 25° and the air cutting angle C1 is 45°. The number of conical fan blades is odd.

The air guide cover 2 has a bell-shaped shape. The air guide cover 2 is as close as possible to the conical fan blades 1. The taper D is 6°-8° smaller than the taper of the fan blades 1; the air supply section between two fan blades is reduced appropriately and gradually in the whole process (the air volume is reduced after compression); the flow rate is kept as consistent as possible when the flow direction is changed; a “siphon effect” is generated at the front and rear ends of the fan blades; the pressure difference between the two sides of the fan blades is minimized; the drive resistance is minimized and the wind pressure is increased exponentially (500-700 pa or higher).

The directional air guide blade 3 makes the spiral outlet air flow to axial direct flow, reducing the friction resistance between the air flow and the components with no air.

The housing 4 is a cylindrical housing, and it will be understood that the housing 4 may also be of other shapes. 

What is claimed is:
 1. An oblique flow fan, wherein it comprises fan blades, an air guide cover, directional air guide blades and a housing, wherein the fan blades and the directional air guide blades are connected through a central bearing, the bearing fixed at the center of the conical fan blades passes through a reserved hole in the center of the directional air guide blades and is fixed, the air guide cover is directly stuck at the corresponding position on the housing through the action of a clamping point, and the directional air guide blades and the housing are fixed through screws.
 2. The oblique flow fan according to claim 1, wherein the fan blades is conical.
 3. The oblique flow fan according to claim 1, wherein the conical blades has a taper A of 50°-60°.
 4. The oblique flow fan according to claim 1, wherein the inclination angle range between the conical fan blade and the axial direction is greater than B1 and less than B2, wherein the inclination angle B1 is 45° and the Inclination angle B2 is 65°.
 5. The oblique flow fan according to claim 4, wherein the number of conical blades is odd.
 6. The oblique flow fan according to claim 1, wherein the air guide cover has a bell mouth cone, the air guide cover is close to the fan blades, and the air guide cover taper D is 6°-8° smaller than that of the fan blades.
 7. The oblique flow fan according to claim 1, wherein the inclination angle E between the tangent line of the initial arc section of the air guide blade and the axial direction is about 45°.
 8. The oblique flow fan according to claim 7, wherein the number of the directional guide blades is even, which is only one more than the number of the fan blade.
 9. The oblique flow fan according to claim 1, wherein the housing is cylindrical. 